Read a Reddit thread

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Goes well beyond the readOnlyHint annotation by disclosing concrete behavioral traits: comments arrive as a flat list in Reddit's own order, reply nesting and scores are unavailable over RSS, and the RSS feed is heavily rate-limited so calls are queued and may take a minute or more each. The serialization constraint ('Call tools one at a time') is actionable operational context an agent could not infer from annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, front-loaded with the core purpose before limitations. Every sentence earns its place: the first establishes what it does, the second describes the return shape, the third covers rate-limit behavior and the concurrency rule.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

There is no output schema, so the description must disclose return semantics, and it does: flat comment list with author, date and text, explicitly noting that nesting and scores are absent. Combined with the latency warning, an agent has everything needed to call this correctly and set expectations.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both 'url' (with example format) and 'comment_limit' (default 50, max 100) are already fully documented in the schema. The description adds no parameter-specific detail beyond that, so the baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Read a post and its comments from a Reddit thread URL') and scopes it to a URL input, which cleanly separates it from the sibling tools search_reddit and browse_subreddit that operate on queries or subreddits rather than a specific thread URL.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description makes the triggering condition clear (you have a thread URL) and adds operational usage guidance ('Call tools one at a time') driven by rate limits. It does not explicitly name when to prefer search_reddit or browse_subreddit instead, but the sibling distinction is largely self-evident from the required URL parameter.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.